A solid-state image element with a photoelectric conversion function is fixed to a package with a preformed wiring, which is used as a solid-state image device. Generally, the package is produced using a ceramic sheet. As an example, a method of producing a package using three ceramic sheets is described as follows.
As shown in FIGS. 13A, 13B, and 13C, predetermined through holes and printed circuits are preformed in ceramic sheets before baking (ceramic green sheets). In this example, holes are punched in a ceramic green sheet 111 to be the top layer and a ceramic green sheet 112 to be an intermediate layer, thus forming openings 114 and 115 for placing solid-state image elements. On the surface of the intermediate layer sheet 112, printed circuits 116 are formed. In these sheets 111 and 112 and a ceramic green sheet 113 positioned to be the bottom layer as a seating for the solid-state image elements, holes are punched to form through holes 117, 118, 119, 120, 121, and 122. These through holes having circular cross sections are positioned along virtual parting lines 124, 125, and 126 arranged in a reticulated form on the surfaces of the respective sheets. These through holes are formed for preventing corners from being broken (through holes 117, 119, and 121) or for providing outer leads to be connected to the printed circuits (through holes 118, 120, and 122).
As a next step, the three ceramic sheets are laminated with the parting lines of the respective sheets coinciding with respect to the lamination direction. As shown in FIG. 14, in this laminate 130, cuts 127 in the form of broken lines are provided along the parting lines in order to facilitate the dividing of the laminate carried out later. This laminate is baked and then is divided along the parting lines (breaking). The individual pieces thus produced are used as packages receiving solid-state image elements.
In a camera using a solid-state image device, it is important for securing optical characteristics to position a lens block and a solid-state image element at predetermined locations and then to fix them. The reason is that when an optical axis of a lens and a (design) optical axis of the solid-state image element do not coincide with each other, the characteristics deteriorate due to shading caused by unevenness in sensitivity or the like. Usually, the lens block is positioned with reference to a package of the solid-state image device. Therefore, accurate positioning of the package is required in both the cases of mounting the solid-state image element and positioning the lens block.
Conventionally, the positioning of the package has been carried out by, for example, the method illustrated in FIG. 16. In this method, a package 102 is positioned by being pressed against an L-shaped positioning jig 151. In this case, the package 102 is positioned with reference to the whole side ends 103 and 104 adjacent to each other via a corner. In this state, a solid-state image element 101 is fixed. Further, the package also is positioned by being pressed against a lens block with an L-shaped fixing portion similar to the above-mentioned positioning jig, and then the solid-state image device and the lens block are positioned with respect to each other.
JP 10-326886 A discloses a solid-state image device with a package 132 in which a substantially V-shaped pilot portion 135 and a substantially U-shaped guide portion 136 are formed as positioning notches as shown in FIGS. 17A and 17B. As shown in FIG. 18, a positioning pilot pin 137 and a positioning guide pin 138 are inserted into the pilot portion 135 and the guide portion 136 respectively, and the pilot portion 135 is pressed against the pilot pin 137 while the guide pin 138 is guided by the guide portion 136, thus positioning the solid-state image device. The guide pin 138 prevents the solid-state image device from rotating.
As described above, packages for solid-state image devices are produced by dividing a ceramic baked product. Therefore, it is difficult to cut and divide the ceramic baked product accurately along parting lines, and as shown in FIG. 15, a so-called “burr” 128 may be produced at a side end of a package in some cases. The projection of the “burr” at the side end has been a factor causing the deterioration in accuracy in the positioning of a package using the positioning jig as shown in FIG. 16.
In the positioning method using the positioning pins as shown in FIG. 18, the projection at the side end of the package does not affect the positioning accuracy. However, since it is required to form notches 135 and 136 for inserting positioning pins at a pair of opposed side ends, the size of the package cannot be reduced. In addition, because of a clearance in the guide portion 136 required for inserting the guide pin, the rotation cannot be prevented by the guide pin sufficiently.